BREAST CYTOPATHOLOGY

Collagenous Spherulosis 39
• Lymphomononuclear inflammatory cells
• Rarely fat necrosis (in cases of recent surgery/biopsy)
• If significant atypia, can lead to erroneous false-positive
diagnosis of cancer on aspiration
Pitfalls and Differential Diagnosis
• Atypical lobular hyperplasia
• Ductal or lobular carcinoma
Collagenous Spherulosis
Collagenous spherulosis is an uncommon lesion, first described
in 1987, characterized by the presence of distinct globules of
amorphous material that resemble adenoid cystic carcinoma
histologically and cytologically.
Clinical Features
• Usually an incidental microscopic finding, often accompanying
benign proliferative lesions of the breast such as
sclerosing adenosis, radial scar, and intraductal papilloma
• Can be unifocal or multifocal
Cytomorphologic Characteristics
(Figures 2.21 to 2.25)
• Smears are moderately cellular with monolayered fragments
of epithelium, often with a focal branching papillary
architecture
• Metachromatic “hyaline” globules (on Diff-Quik stain),
pale green and vaguely translucent (on Papanicolaou stain),
usually well formed, surrounded by monomorphic ductal
epithelial cells
• Higher magnification reveals fibrillar structures of the
globules, which often vary in size